1. Technical Field
The present disclosure relates to a vehicle control apparatus for controlling an inter-vehicle distance between a vehicle carrying the apparatus and a preceding vehicle.
2. Related Art
A known vehicle control apparatus, as disclosed in the international publication WO2014/038076, is configured to control travel of a vehicle carrying the apparatus (hereinafter referred to as a subject vehicle) to bring an inter-vehicle distance between the subject vehicle and a preceding vehicle to a target inter-vehicle distance. Such a vehicle control apparatus may use a radar device to transmit radar waves to the front of the subject vehicle and receive reflected waves from a target to generate target information about the target. The target information includes a separation distance between the subject vehicle and the target, a relative speed and a lateral position of the target relative to the subject vehicle, and others.
Further, based on the target information, two or more targets, among a plurality of targets, that exhibit the same behaviour are determined as belonging to the same preceding vehicle, and the inter-vehicle distance control is implemented to follow the target that is closest to the subject vehicle among the two or more targets on the same preceding vehicle (hereinafter referred to as a rear-end target). A separation distance between the rear-end target and another one of the two or more targets that is forward of the rear-end target (hereinafter referred to as a forward target) is stored as an offset. This allows a position of the rear-end target to be estimated using the offset and a detected distance from the subject vehicle to the forward target even when the rear-end target is no longer detected, for example, upon the subject vehicle approaching the preceding vehicle. Thus, the inter-vehicle distance control to follow the rear-end target of the preceding vehicle can be continued.
However, in the presence of two targets on the preceding vehicle, one forward of the other, the two targets may not remain unchanged in fore-and-aft position, but either or both of the two targets may be forward or rearward displaced unexpectedly due to various factors. Then, there is concern that the inter-vehicle distance control cannot be implemented correctly without taking into account such displacement.
In consideration of the foregoing, exemplary embodiments of the present disclosure are directed to providing a vehicle control apparatus capable of properly implementing inter-vehicle distance control of a vehicle carrying the apparatus behind a preceding vehicle.